Stihl BR 420 Instruction Manual

Pages 70

Year 2006

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of 70

Stihl BR 420 Specification

The Stihl BR 420 is a professional-grade backpack blower designed for efficient and powerful outdoor cleaning tasks. Engineered for durability and performance, it is equipped with a robust 56.5 cc two-stroke engine that delivers high air velocity and volume, making it suitable for heavy-duty applications. The blower features a maximum air speed of approximately 172 mph and an air volume of up to 1,098 cubic meters per hour, ensuring effective clearing of leaves, debris, and other unwanted materials. An ergonomic design enhances user comfort, incorporating adjustable harness straps and a padded backrest to reduce operator fatigue during extended use.

The Stihl BR 420 includes an advanced anti-vibration system to minimize vibrations, further contributing to user comfort and control. The blower tube is designed to be easily adjustable, allowing users to customize the length for optimal performance and reach. A large fuel tank capacity ensures longer operating times between refueling, increasing efficiency for professional users. The starting mechanism is designed for reliability, featuring a simplified starting procedure with an automatic choke reset and a semi-automatic decompression valve to reduce the effort needed to start the engine.

Constructed with high-quality materials, the BR 420 is built to withstand the demands of frequent use. Its lightweight frame, combined with a well-balanced design, facilitates maneuverability and ease of handling. The air filter is accessible for quick maintenance, ensuring the engine operates smoothly and efficiently over time. Overall, the Stihl BR 420 stands out as a powerful and reliable tool for landscaping professionals seeking a high-performance solution for outdoor cleaning tasks.

Stihl BR 420 F.A.Q.

How do I start the Stihl BR 420 blower?

To start the Stihl BR 420, first ensure the fuel tank is filled and the blower is on a flat surface. Set the choke lever to the "cold start" position, press the primer bulb several times until fuel is visible, and pull the starter cord until the engine fires. Move the choke to "run" and pull the cord again to start the engine.

What type of fuel should be used in the Stihl BR 420?

The Stihl BR 420 requires a 50:1 ratio of unleaded gasoline to two-stroke engine oil. Use fresh, high-quality gasoline with a minimum octane rating of 89, and mix it with Stihl’s two-stroke engine oil for optimal performance.

How can I troubleshoot if my Stihl BR 420 won't start?

If the BR 420 won't start, check the fuel level and ensure the fuel is fresh. Verify the spark plug is clean and properly gapped. Examine the air filter for obstructions and ensure the choke is in the correct position. If these don't resolve the issue, the carburetor may need adjustment.

How often should I clean the air filter on the Stihl BR 420?

The air filter should be inspected before each use and cleaned regularly, especially in dusty conditions. A thorough cleaning is recommended after every 10 hours of operation to ensure optimal engine performance.

What maintenance steps should be performed regularly on the Stihl BR 420?

Regular maintenance includes checking and cleaning the air filter, inspecting and replacing the spark plug as needed, checking fuel lines for leaks, and cleaning the cooling fins. Additionally, ensure the fuel mixture is fresh and correctly mixed.

How do I adjust the carburetor on the Stihl BR 420?

To adjust the carburetor, first ensure the air filter is clean and the engine is warmed up. Turn the low-speed and high-speed screws gently clockwise until they stop, then back them out one full turn. Adjust as needed to achieve smooth idling and acceleration.

What should I do if the Stihl BR 420 is vibrating excessively?

Excessive vibration can be caused by a loose or damaged fan, or debris lodged in the fan housing. Inspect the fan for damage and ensure it is securely attached. Remove any debris and ensure all screws and bolts are tight.

How do I store the Stihl BR 420 for the off-season?

For off-season storage, drain the fuel tank and run the engine until it stops to clear the carburetor. Clean the blower thoroughly and check for any damage. Store the unit in a dry, cool place away from direct sunlight and moisture.

What is the correct spark plug gap for the Stihl BR 420?

The correct spark plug gap for the Stihl BR 420 is 0.5 mm (0.020 inches). Ensure the spark plug is clean and properly gapped to maintain efficient engine performance.

How do I replace the starter cord on the Stihl BR 420?

To replace the starter cord, remove the starter assembly from the engine. Remove the old cord and attach a new one of the same length and thickness. Wind the cord around the pulley, reattach the handle, and reinstall the starter assembly.